How do I get meaningful error messages in IIS7?

I have moved this question to Server Error , where it is probably more appropriate.

I have a classic ASP website that crashes in IIS7. This fails because IIS does not allow uploading files larger than a certain size. I know this because files below 200k work fine. I removed the "Status Code 500" error in IIS, but still didn't get the file name and the line where my code failed, as when running locally.

Instead, I get:

The page cannot be displayed because an internal server error has
occurred.
If you are the system administrator please click here to find out 
more about this error.

How do I get the filename and the line where my code crashed?

Here are my IIS settings:

_{(source: yart.com.au )}

AND ANSWER FROM THE SERVERFALT ...

Log in as an administrator on the IIS server, open IIS 7 Manager, open the Asp icon under the website for which you want to change the error messages (it will be on the right with all the other icons; this is the first one).

Scroll down and set Send errors to browser to True. Maybe iisreset is needed, not sure.